Reduced-reactivity-swing LEU fuel cycle analyses for HFR Petten

The primary objective of these low enriched uranium (LEU) fuel cycle analyses was to effect at least a 33% reduction in the reactivity swing now experienced in the high enriched uranium (HEU) cycle while minimizing increases in 235U loading and power peaking. All LEU equilibrium fuel cycle calculations were performed using either a 19- or 20-plate fuel element with 0.76-mm-thick meat and 0.5- or 0.6-mm-thick Cd wires as burnable absorbers and 16- or 17- plate control rod fuel followers with 0.76-mm-thick meat. Burnup-dependent microscopic cross sections were used for all heavy metals and fission products. A three-dimensional model was used to account for the effect of partially inserted control rods upon burnup profiles of fuel and of burnable absorbers and upon power peaking. The equilibrium cycle reactivity swing (or, equivalently control rod movement) was reduced by 50% using LEU fuel with U meat densities <4.8 Mg/m3. (author)